Comparisons of Tree Growth Ring Diameter Between

Quercus falcate, Pinus taeda, and Juniperus virginiana

Jennifer Luther, Carl Chmielewski, and Ryan Grubb

Research Question

• Ho: There is no difference in the average diameter of growth rings between Quercus falcate, Pinus taeda, and Juniperus virginiana

• Ha: There is a difference in the average diameter of growth rings between Quercus falcate, Pinus taeda, and Juniperus virginiana

Quercus falcata (Southern Red Oak)

• 20-25 m in height• 60-90 cm DBH• Humid, temperate climate• Upland tree with well

drained soil• Moderately fast growing

Pinus taeda (Loblolly Pine)• Max height 49.7 m• Max DBH 143 cm• Humid, warm-temperatures

• High day temps increase growth• High night temps decrease growth

• Wide range of moisture levels• Rapidly growing juvenile

growth

Juniperus virginiana (Eastern Red Cedar)

• 12-37 m in height• 30-122 cm DBH• Variety of climates• Variety of moisture levels• Growth rate depends on

site characteristics

Selection and GPS Location of Southern Red Oak

Selection and GPS location of Loblolly Pine

Selection and GPS location of Eastern Red Cedar

Dendrochronology• Uses tree rings to analyze

temporal and spatial patterns from the past

• Increment borer removes tree core

• Width between rings were measured to find growth per year

• Statistics and graphs were developed using R-Studio and Excel

Variables of Study

• Dependent variable: growth of each species per year

• Independent variable: The three species (Southern Red Oak, Loblolly Pine, and Eastern Red Cedar)

• Mean Growth Per Year:• Loblolly Pine – 4.92 mm• Southern Red Oak – 2.23

mm• Eastern Red Cedar – 11.74

mm

Total Growth PercentLoblolly Pine: 1.72%Southern Red Oak:

0.65%Eastern Red Oak: 4.33%

• Mean DBHLoblolly Pine – 992.03 mm

Southern Red Oak – 2042.25 mm

Eastern Red Cedar – 1054.42 mm

• Mean RPI• Loblolly Pine - 151.13 mm

• Southern Red Oak - 297.18 mm

• Eastern Red Cedar – 57.15 mm Loblolly Pine Southern Red Oak Eastern Red Cedar0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

Grow

th %

Yearly growth comparison of 3 species over 10 year span

2005 2006 2007 2008 2009 2010 2011 2012 2013 20140

2

4

6

8

10

12

14

Loblolly Pine Southern Red Oak Eastern Red Cedar

Aver

age

ring

wid

th (m

m)

Total Growth for 10 Year Span

Loblolly Pine: 49.2 mmSouthern Red Oak: 22.35

mmEastern Red Cedar:

117.45 mm

Loblolly Pine Southern Red Oak Eastern Red Cedar0

20

40

60

80

100

120

140

Tota

l 10

Year

Rin

g W

idth

(mm

)

Frequency of Tree Ring Width for Loblolly Pine

Range = 11Number of Class = 12

Class Width = 0.92

.5 -

1.5

1.5

- 2.5

2.5

- 3.5

3.5

- 4.5

4.5

- 5.5

5.5

- 6.5

6.5

- 7.5

7.5

- 8.5

8.5

- 9.5

9.5

- 10.

5

10.5

- 11

.5

11.5

- 12

.5

0

5

10

15

20

25

30

35

40

45

Tree Ring Width (mm)

Freq

uenc

y

Frequency of Tree Ring Width for

Southern Red OakRange = 7.5

Number of Classes = 9Class Width = 0.83

0 - 1

.33

1.33

- 1.8

3

1.83

- 2.33

2.33

- 3.8

3

3.83

- 4.3

3

4.33

- 5.8

3

5.83

- 6.3

3

6.33

- 7.8

3

7.83

- 8.3

3

0

10

20

30

40

50

60

70

Tree Ring Width (mm)

Freq

uenc

y

Frequency of Tree Ring Width for Eastern Red

CedarRange = 13

Number of Classes = 14Class width = 0.93

4.07 -

5.93

5.93 -

6.07

6.07 -

7.93

7.93 -

8.07

8.07 -

9.93

9.93 -

10.07

10.07

- 11

.9311

.93 -

12.07

12.07

- 13

.9313

.93 -

14.07

14.07

- 15

.9315

.93 -

16.07

16.07

- 17

.9317

.93 -

18.07

0

10

20

30

40

50

60

70

Tree Ring Width (mm)

Freq

uenc

y

Test for Normality and Homogeneity of Variance

Shapiro-Wilks• Loblolly Pine

• P-value = 0.38

• Southern Red Oak• P-value = 0.87

• Eastern Red Cedar• P-value = 0.095

Bartlett Test for ring width growth• K-squared = 4.96• df = 2• P-Value = 0.084

ANOVA for ring width growthdf Sum sq Mean sq F-value Pr(>F)

Species 2 480.8 240.38 1514 <2e-16Residuals 27 4.3 0.15

TukeyHSD for ring widthSpecies Diff Lwr UprOak-Cedar -9.51 -9.95 -9.07Pine-Cedar -6.82 -7.27 -6.38Pine-Oak 2.68 2.24 3.13

Conclusions

• Due to the extremely small p-value found when running the ANOVA, we reject the Ho

• The TukeyHSD showed a significant difference between all species, but there was a significant range between the Eastern Red Cedar and the other two species.

References

• Belanger, R. P., Krinard, R. M. 2004. Silvics of Forest Trees of the United States. USDA Ag Handbook. 654:2.

• Grissino-Mayer, H. D. The Science of Tree Rings. The University of Tennessee. Available at: http://web.utk.edu/~grissino/index.htm.